The invention has been developed primarily for use in extracting toner powder from toner cartridges, and will be described predominantly with reference to this application. It will be appreciated, however, that the invention is not limited to this particular field of use, being also applicable to other applications where separating a powder material from larger pieces is required.
Toner printing technology has been almost universally adopted in photocopiers and computer printers. These devices commonly have an internal reservoir for storing toner powder which is used in the printing process. Initially, these reservoirs were fixed to the machine and required manual refilling by pouring toner from a refill packet. Nowadays, in an attempt to limit direct contact with the messy toner powder, replaceable toner cartridges have largely superseded refillable reservoirs. Cartridges are filled in a factory where the distribution of toner powder can be strictly controlled to minimise and isolate spillage.
The popularity of disposable cartridges has meant the number of cartridges discarded has increased exponentially in recent years. Used cartridges may, in some cases, be recycled and recharged a number of times by a specialist reconditioner. Eventually however, all cartridges are either stripped down for their materials or more often, thrown out altogether. Either of these alternatives presents their own particular problems.
The cartridges are generally a combination of thermoplastic resins and ferrous and non-ferrous metals. These materials are slow to break down naturally and thus present a significant environmental pollutant. In addition, it is rare that toner cartridges are entirely empty when they are replaced. Often 5% to 10% of the toner capacity of the cartridge remains when discarded. This figure can be as high as 100% if the cartridge is faulty, has been superseded or past its use by date. The residual toner also presents a significant environmental hazard when the cartridges are thrown out. However, whilst toner along with the materials which make up the cartridges are recyclable, the nature of toner powder makes stripping the cartridges difficult.
Toner is a very fine powder and will readily become airborne and circulate with airflow. As such it can be easily inhaled and may be a significant health issue with workers. Moreover, as with many fine powders, when airborne, in the right concentration and conditions it can ignite and explode.
Currently the stripping and materials separation of cartridges is carried out manually. This not only places those doing the stripping in a high risk environment, it is also labour intensive and expensive. In modernised countries, which are the greatest users of these printer cartridges, labour cost are high meaning the manual dismantling of cartridges is not cost effective.
It is an object of the present invention to overcome or ameliorate one or more of these disadvantages of prior art, or at least to provide a useful alternative.